At times your device may become "unbolted" and you will receive an error when trying to take a credit card payment. Here are some help docs from CardConnect to help get the devices "bolted" again.
First step is to restart the device to force it to power cycle. The majority of the times, this will fix your issue.
- iPP350 and iSMP4: Press the # and yellow key simultaneously to restart
- Clover Mini: Tap all 4 corners of screen simultaneously to access Merchant Mode. This will allow you to verify the network connection and restart the device through the notification menu
If restarting your device does not work, please confirm you network connection or contact your IT department about whitelisting. This article contains all necessary information that the IT department will need to setup the network to support the terminal.
Next, if your device is still not working properly, you will want to check the following troubleshooting sites for your device.